Rage, Louis J., author
Scranton, Penn., International Textbook
Buku Teks
Riggs, James L., author
John Wiley & Sons, 1970
Buku Teks
Riggs, James L., author
John Wiley & Sons, 1987
Buku Teks
Hull, John F., author
Gower Press, 1973
Buku Teks
Buffa, Elwood S. (Elwood Spencer), author
John Wiley & Sons, 1975
Buku Teks